Continuous Treatment With Ixekizumab Less Likely to Result in Flares in axSpA

The recapture of response with ixekizumab retreatment in patients with axial spondyloarthritis (axSpA) who experienced a flare after withdrawal of ixekizumab therapy was assessed in a study published in Annals of the Rheumatic Diseases.

COAST-Y is a phase 3, multicenter, long-term extension study (ClinicalTrials.gov Identifier: NCT03129100) of ixekizumab recapture and retreatment rates in patients with axSpA. The COAST-Y trial included a lead-in period and a double-blind placebo-controlled randomized withdrawal-retreatment period.

For the 24-week lead-in period, patients received 80 mg of ixekizumab every 2 weeks or every 4 weeks. On completion of the lead-in period, patients who achieved remission with ixekizumab were entered into the randomized withdrawal-retreatment period.

Remission was defined by an Ankylosing Spondylitis Disease Activity Score (ASDAS) of less than 1.3 at week 16 or week 20.

In the withdrawal-retreatment period, patients were assigned 1:1:1 to receive ixekizumab every 2 weeks, ixekizumab every 4 weeks, or placebo. Patients were followed-up for the development of flares, defined as an ASDAS score of at least 2.1 at 2 consecutive visits or an ASDAS score of greater than 3.5 at any visit. Patients who experienced a flare were reassigned to open-label ixekizumab and received the same dose as during the lead-in period.

A total of 773 patients were enrolled in the COAST-Y trial, among whom 155 achieved remission and entered the randomized withdrawal-retreatment period (placebo, n=53; ixekizumab every 2 weeks, n=54; ixekizumab every 4 weeks, n=48).

Of the patients who received placebo, 28 (53%) experienced a flare during weeks 24 to 104. Among the patients who experienced flares, 4 (14%) recaptured ASDAS low disease activity before ixekizumab retreatment; 23 (82%) recaptured low disease activity with retreatment; and 19 (68%) achieved inactive disease with retreatment. Of the 102 patients who received continuous treatment with ixekizumab, 13 (12.7%) experienced a flare, among whom 7 (54%) were able to recapture low disease activity before switching to open-label treatment. The remaining patients recaptured low disease activity with open-label treatment, with 4 (31%) achieving inactive disease after switching.

Overall, patients with axSpA receiving continuous treatment with ixekizumab were less likely to experience flares compared with patients who switched to placebo. However, most patients were able to recapture low disease activity and inactive disease with ixekizumab retreatment.

“These data may provide support to patients who require interruption in active therapy,” the researchers noted.

Disclosure: This research was supported by Eli Lilly and Company. Please see the original reference for a full list of authors’ disclosures.